J. Michael Pearson, Valeant Pharmaceuticals chairman & CEO, weighs in on news that Allergan has adopted a "poison pill" defense strategy. Also Pearson shares his thoughts on adding some of Allergan's notable cosmetic products like Botox and Restasis to its growing arsenal.

J. Michael Pearson, Valeant Pharmaceuticals chairman & CEO, explains why he decided to pursue Allergan and shares his R&D business model, with CNBC's Kate Kelly. This year we are launching 19 products in the United States, says Pearson.